Earlier quoted context omitted.
In what sense is this a 'biased statement' exactly? If a dozen of the top climate scientists put out a statement saying that fighting climate change should be a serious priority (even if they can't agree on one easy solution) would that also be 'biased'?
Climate change is a generally accepted phenomenon. Extinction risk due to AI is not a generally accepted phenomenon.
"This signatory might have alterior motives, so we can disregard the whole statement"
"We haven't actually seen a superintelligent AI/manmade climate change due to CO2 yet, so what's the big deal?"
"Sure maybe it's a problem, but what's your solution? Best to ignore it"
"Let's focus on the real issues, like not enough women working in the oil industry"